Audiologic tests, such as tympanometry and/or an otoacoustic emission test, examines the condition of the middle ear, mobility of the tympanic membrane, and/or the conduction bones by creating variations of pressure in the ear canal. In order to modify the pressure, a probe is inserted into the ear canal creating an air tight seal of the ear canal.
Audiologic tests are conventionally performed by transmitting a continuous tone with a primary frequency component at a primary frequency of 226 Hz towards the tympanic membrane and measuring via a microphone the signal reflected by the tympanic membrane. The choice of 226 Hz is a de facto standard in performing a tympanometry in adults. In small children a tympanometry is occasionally performed with a tone with a primary frequency component at a primary frequency about 1,000 Hz.
Conventionally apparatuses configured to perform audiologic tests incorporate measures to automatically detect if the probe is inserted into the ear. This is conventionally achieved by transmitting, through the test probe, the test tone, e.g. 226 Hz, whenever the apparatus is switched on. The microphone detects a reflection of the test tone, and the reflection is an indicator that the test probe is inserted into an ear canal. However, the reflection may indicate that the test probe is inserted into an ear canal, even if an air tight seal is not created. Hence, the apparatus may activate a pump to increase/decrease pressure even if the test probe is not correctly positioned in or at the ear canal.